The U.S. on Wednesday reported its biggest increase in consumer prices in a year, pushing stocks lower in early trading.

The consumer price index, which follows the costs of household goods and services, advanced by a half percentage point in January, up from two-tenths of a point in December.

The January increase pushed the year-over-year inflation rate up by 2.1 percent. It was the same 12-month rate recorded in December, increasing fears among investors that firming inflation, along with increasing wages paid to American workers, could lead policymakers at the country's central bank, the Federal Reserve, to boost interest rates at a faster pace.

The Labor Department said consumer prices, minus the volatile changes in food and energy costs, rose three-tenths of a percentage point in January, the largest increase since January 2017. Analysts had been expecting an increase of 0.2 percent.

Stock indexes were lower at the start of Wednesday, with the key Dow Jones industrial average falling about a third of a percentage point after a string of recent days with massive swings between losses and gains.